<template>
  <div>
    <div class="father">
      <div class="box" @click="id=1" :class="{active:id===1}">1</div>
      <div class="box" @click="id=2" :class="{active:id===2}">2</div>
      <div class="box" @click="id=3" :class="{active:id===3}">3</div>
    </div>
  </div>
</template>

<script>
export default {
  data() {
    return {
      id:1
    }
  },

  methods: {},
}
</script>

<style scoped>
.box {
  border: 1px solid #333;
  width: 250px;
  height: 250px;
}
.father {
  display: flex;
}
.active {
  background-color: #087;
}
</style>
